Circuit breaker



April 28, 1931. SPEiSER 1,802,679

CIRCUIT BREAKER Filed J an. 24, 1928 ATTORNEY Patented Apn28, 1933i;

UNITED s'rarss teasers PATENT orsicli TRIO & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA emetic essence Application filed January Q4, 1958, Serial l lo. 249,109, and in Germany March it, 1927 My invention relates to circuit breakers and particularly to circuit breakers for controlling small motors and lighting circuits.

An object of my invention is to provide a circuit breaker wherein the contacts are releasably maintained in closed position and wherein the retaining means is released in response to overload and short-circuit conditions.

A further object of my invention is to provide a circuit breaker having the shove-noted characteristics, wherein the circuit loreelrer is released to open position Toy a current-responsive thermal element after an overload hes endured for a predetermined time and where in the circuit breaker is released to open position by an electromagnet trip mechanism in a nu response to a short-circuit.

A further object of my invention is to provide a circuit hreakervvith an electromegnet trip mechanism that is also ectuatecl by s current-responsive thermal element,

These and other objects thet will he made apparent throughout the further description of my invention are attained lay metres of the apparatus hereinafter described illustrated in the accompanyin wherein The figure is e longitudinal a circuit breaker embodying re invention.

Referring to the drawing, breaker comprises en lilslllt lllll'i which a stationary centsct mounted and which is adopted by a movable cont-act niernher by a yielding contact arm s secured to a terminal 6 mounted. upon the hose 2.,

The contact arm 5 is sctneted h of s toggle device comprising three l 9. The link 7 is pivotslly connected to the terminal 6 and the link 9 is c nnected to an. operating handle ll that is mounted for .rotation about a, shaft l2 csrried by e, frame member 13 that is attached to the hose 2. The contact arm 5 extends between 2 pivot shaft 14 of the toggle and a stop lug 15 on the link 7, which affords a lost-motion connection he= tween the tog le mechanism and the contact arm. The lin 8 is provided with an adjusting screw 16 that engages the limit 9 and linr its the over-center position of the knee pivot 17 of the toggle.

It will be seen from the foregoing that when the knee pivot 17 is moved past the cen ter line connecting the pivot shafts "it and 18, the toggle will collapse and the yielding con tact arm 5 will immediately snap to open position, Rotation of the operating handle ill in the clockwise direction will also cause collepse of the togvl and suhsequentopening of the circuit breaker. l hen the operating hendle is moved in a counterclockwise direction, assuming that the circuit breaker is in open position, the toggle links will assume thepo sition shown in the figure and releesehly maintain the contact l in engagement with the contact 8,

The current-responsive trip mechanism for the circuit breaker comprises a. solenoid coil 19 that is mounted on the frame ill. The coil is provided with e centrally-disposed guide tuloe 21 that is provided near its lower wi h its upper end -with a guide bush ng serves as a guide for or t sleeve 24 that is "Quiche-(l to an j at is mounted i'cr recicrocation Wit sleeve 21. L

1 time,

mature sleeve 2 is provided at its upper end with a disc that is adapted to he hy the armature sleeve and move to engagement with the knee joint of the le links 8 and 9 when the armature 25 is reed upwardly by a sudden current surge in the coil l9 as the result of short-circuit condition. The plunger 26 is "forced upwardly with sufficient force to hrcal e tog;- gle and cause opening movement e cir cuit hreaker.

The plunger 26 is supported; s hell crank lever 29 that is pivoted upon e lease by means of a shaft 31. The short srm 32 of the bell crank lever engages the free end of s oi-metal thermal element t" a secured at its upper end to the it and the terminal 6. The bi-metal element is provided with a heating element 34 that is connected in series with the circuit breaker conen armature supporting collar 22 end i it i 1 4,

lne trip plungel extends through the srilO tacts and the solenoid coil 19. The position of the armature within the coil 19 may be varied by adjusting the position of the armature supporting disc 22 within the sleeve 21; The disc 22 is maintained in adjusted position by the screw that extends through a slot 36 in the lower end of the sleeve 21. By varying the positions of the armature stop disc 22, the amount of current required to cause operation of the solenoid and subsequent opening of the circuit breaker may be varied and so adjusted that the normal starting current of the motor controlled by'the.

circuit breaker will not cause the circuit breaker to trip open.

The current-responsive thermal element is provided to cause the circuit breaker to be opened under short-circuit conditions after they have persisted for a predetermined time.

Thus, the circuit breaker may be opened by a current less than the starting current of the motor, in the event that it endures for suflicient time, the thermal element being proportioned to open the circuit before injury is done to the apparatus controlled thereby.

It is apparent from the foregoing that the current-responsive thermal element may actuate the circuit breaker independentl of the solenoid or electromagnet and that t e electromagnet may operate the circuit breaker independently of the operation of the thermal element and that the adjustment of the solenoid armature within the solenoid in no way affects the adjustment of operation of the thermal element.

lVhile I have illustrated but one embodiment of my invention, it will be apparent to I means having a movable armature for actumember in closed position, an electromagnet having a movable armature, a trip memberoperable by the armature for actuating the said means and a current-responsive thermal element for actuating the trip member independently of the said armature.

4. A circuit breaker comprising a movable contact member, releasable means for retaining the switch member in closed position, an electroma net having a movable armature,

a trip member-operable by the armature for actuating the said means, a currentresponsive thermal element and a lever connecting the said element and the trip memher, the said trip member being movable independently of the said lever.

5. A circuit breaker comprising a contact through the opening in the solenoid coil andmovable therein into tripping engagement with the releasable means by the magnetic flux of the said coil and the said thermal element. j

6. A circuit breaker comprising a contact member, a movable switch member normally biased to open position, a solenoid coil responsive to current in the circuit controlled by the switch member, and having an opening extending therethrough, a thermal element res onsive to current in the circuit controlled y the switch member, releasable means for retaining the switch member in closed position, and trip means extending through the opening in the said coil for actuating the said releasable means and operable by the magnetic flux of the said coil and the thermal element.

In testimony whereof, I have hereunto subscribed my name this 19th day of December,

GOTTLIEB SPEISER. 

